Hydrochloric Acid → Methyl [3-bromo-4-(3-fluorobenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl]-acetate

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Reaction Steps

1.50 g (4.69 mmol) of the compound from Example 137A are stirred under reflux for 4 hrs together with 508 mg (4.69 mmol) of methyl chloroacetate and 1.30 g (9.4 mmol) of potassium carbonate in 33 ml acetonitrile. After cooling, the mixture is neutralized with 1 N hydrochloric acid and diluted with ethyl acetate. The organic phase is separated, washed with saturated sodium chloride solution, dried over sodium sulphate and freed of the volatile components on the rotary evaporator. The residue is dissolved in 20 ml dichloromethane and absorbed onto 3 g of diatomaceous earth. After removal of the solvent on the rotary evaporator the solid is transferred to a silica gel chromatography column and the product purified by elution with cyclohexane/ethyl acetate (gradient 5:1→1:1). 1.36 g (84% of theory) of the title compound are obtained.

Provenance & Evidence